JP2008223957A - Double row ball bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a double row ball bearing whose torque can be reduced by keeping an adequate amount of lubricant in the bearing to suppress the agitating resistance of the lubricant. <P>SOLUTION: The lubricant is supplied to the small diameter side of the bearing 1, and the lubricant is moved to the large diameter side of the bearing 1 with the pumping operation of the bearing 1. An outer ring 2 has a lubricant discharge passage 8 for discharging the lubricant from a middle between balls 4, 5 in double rows to the outside. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a double row ball bearing, and more particularly to a double row ball bearing suitable for supporting a pinion shaft that is lubricated by using a lubricant contained in the device in an automobile final reduction gear or the like. About.

  A tandem type double-row ball bearing having an outer ring, an inner ring, a plurality of balls arranged in a double row between both wheels, and a retainer for holding these balls, Widely used in pinion shaft support devices and the like.

  FIG. 2 shows an example of a differential gear device to which the double row ball bearing according to the present invention is applied. The differential gear device is rotatably supported by a housing (41) and a pinion gear ( 43) provided with a pinion shaft (42), a ring gear (44) meshed with the pinion gear (43), and a pair of inner and outer sides for rotatably supporting the pinion shaft (42) on the housing (41). Double row ball bearings (45), (46) and a drive shaft coupling flange joint (47) provided at the outer end of the pinion shaft (42) are provided.

In this differential gear device, the lubricating oil splashed with the rotation of the ring gear (44) passes through a lubricating oil passage (48) in the housing (41), and a pair of double row ball bearings (45) (46). It is introduced in the middle in the axial direction. When the double row ball bearings (45) (46) rotate, fluid flow (pump action) from the small diameter side to the large diameter side occurs, so the double row ball bearings (45) (46) for differential gear devices The small diameter side of each double row ball bearing (45) (46) is positioned inward in the axial direction, and this pump action is used to lubricate from the small diameter side (just the middle part of a pair of double row ball bearings) However, a lubrication method for discharging oil to the large diameter side is generally applied.
JP 2006-234100 A

  In a pinion shaft support device for a vehicle or the like, reduction of the rotational torque of the bearing has been an issue in order to reduce loss. In order to reduce the rotational torque, it is effective to reduce the amount of lubricant passing through the bearing and suppress the stirring resistance by the lubricant.

  An object of the present invention is to provide a double-row ball bearing that optimizes the amount of lubricant present in the bearing and suppresses stirring resistance due to the lubricant, thereby enabling a reduction in torque.

  The double row ball bearing according to the present invention includes an outer ring, an inner ring, a plurality of balls arranged in a double row between both wheels, and a cage for holding these balls, and the lubricant is moved by the pumping action of the bearing. In the double-row ball bearing to be made, the outer ring is provided with a lubricant discharge passage for discharging the lubricant in the middle part of the double-row balls to the outside.

  The double row ball bearing is, for example, oil bath lubricated, and the lubricating oil flowing in from one end face opening is discharged from the other end face opening by the pump action of the ball bearing (tilted contact ball bearing). At least one lubricant discharge passage is provided in a portion of the outer ring facing the axial intermediate portion of the balls arranged in double rows. Normally, the amount of lubricant supplied into the bearing is not controlled, and the pumping action increases as the rotational speed increases, so the amount of lubricant flowing into the bearing increases as the rotational speed increases. As a result, the agitation resistance of the lubricant increases and the torque increases. According to the lubricant discharge passage provided in the outer ring, the amount of lubricant is easily discharged to the outside due to an increase in centrifugal force, so that the amount of lubricant discharged from this passage increases as the number of rotations increases. The amount of lubricant staying inside the bearing can be maintained properly.

  At least one lubricant discharge passage is provided, preferably a plurality at a predetermined interval in the circumferential direction. In a housing or the like to which the outer ring is attached, a lubricant circulation passage for returning the lubricant discharged from the lubricant discharge passage to the lubricant supply passage is appropriately formed.

  As the double row ball bearing, for example, an outer ring having a double row raceway surface having different diameters, an inner ring having a double row raceway surface corresponding to each raceway surface of the outer ring, and a raceway surface between each row of both wheels A plurality of large-diameter side balls and a plurality of small-diameter side balls arranged with different pitch circle diameters, a large-diameter side retainer that holds the plurality of large-diameter side balls, and a small-diameter side retainer that holds the plurality of small-diameter side balls However, the present invention is not limited to this, and it may be a double row ball bearing in which oblique contact ball bearings having raceway surfaces having the same diameter are combined face to face.

  According to the double row ball bearing of the present invention, since the lubricant discharge passage for discharging the lubricant inside the bearing to the outside is provided in the outer ring, the lubrication discharged from the lubricant discharge passage as the number of rotations increases. By increasing the amount of the agent, the amount of the lubricant staying inside the bearing can be maintained appropriately, and the torque can be reduced.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 shows an embodiment of a double row ball bearing according to the present invention. This double-row ball bearing (1) has a double-row raceway surface (2a) (2b) with different diameters and an outer ring (2) attached to the housing (10), and each raceway surface of the outer ring (2). (2a) (2b) and corresponding double-row raceway surface (3a) (3b) and inner ring (3) attached to the rotating shaft (not shown), and the raceway of each row of both wheels (2) (3) A plurality of large diameter balls (4) and a plurality of small diameter balls (5) arranged with different pitch circle diameters between the surfaces (2a) (3a) (2b) (3b), and a plurality of large diameter balls ( A large-diameter side cage (6) that holds 4) and a small-diameter side cage (7) that holds a plurality of small-diameter balls (5).

  The housing (10) is provided with a lubricant supply passage (10a) for supplying a lubricant to the small diameter side of the double row ball bearing (1). Further, a plurality of lubricant discharge passages (8) for discharging the lubricant inside the bearing (1) to the outside are provided at predetermined intervals in the circumferential direction in the middle of the outer ring (2) in the axial direction. The housing (10) is formed with a lubricant circulation passage (10a) for returning the lubricant discharged from the lubricant discharge passage (8) of the outer ring (2) to the lubricant supply passage (10a). .

  In the figure, the outer diameter of the left raceway surface (3b) of the inner ring (3) is smaller than the outer diameter of the right raceway surface (3a) of the inner ring (3) and the left raceway of the outer ring (2). The inner diameter of the surface (2b) is smaller than the inner diameter of the right raceway surface (2a) of the outer ring (2). The contact angles of the large-diameter side ball (4) and the small-diameter side ball (5) are the same direction (not limited to the same angle). Each retainer (6) (7) is formed in a tapered cylindrical shape whose diameter increases from the left side to the right side as a whole. The lubricant discharge passage (8) is provided at a position corresponding to the right end (discharge side end) of the small diameter side cage (7). Lubricating oil is supplied from the left side (that is, the small diameter side) of the drawing, and is discharged from the right side (that is, the large diameter side) of the drawing by the pump action of the double row ball bearing (1).

  The double-row ball bearing (1) of the present invention is preferably used as a bearing device that rotatably supports the pinion shaft (42) on the housing (41) in the differential gear device of the automobile shown in FIG. The double row ball bearing (1) is lubricated by using a lubricating oil contained in the housing (41). Lubricating oil is accumulated in the lower part of the housing (4), so that the supply amount is not insufficient. When the rotational speed increases, the pump action also increases, and the amount of lubricating oil flowing into the bearing (1) increases. An increase in the amount of lubricating oil leads to an increase in stirring resistance and torque, but in the double row ball bearing (1) of the present invention, as described above, the lubricant discharge passage ( 8) is provided, so that the larger the centrifugal force, the more lubricant is discharged to the outside.As a result, the amount of lubricant remaining in the bearing (1) is maintained appropriately, and torque can be reduced. Become.

  In the above description, the tandem double-row ball bearing (1) having different diameters of the raceway surfaces (2a), (2b), (3a), and (3b) has been described, but the lubricant discharge passage ( The configuration provided with 8) can also be applied to double-row ball bearings having the same raceway diameter. In addition, the double row ball bearing (1) of the present invention can be used not only for supporting the pinion shaft of the differential gear device but also as a bearing for supporting the pinion shaft of the transaxle device.

FIG. 1 is a longitudinal sectional view of an upper half portion showing an embodiment of a double row ball bearing of the present invention. FIG. 2 is a longitudinal sectional view showing a differential gear device as an example in which the double row ball bearing of the present invention is used.

Explanation of symbols

(1) Double row ball bearing
(2) Outer ring
(3) Inner ring
(4) Large diameter side ball
(5) Small diameter side ball
(6) Large diameter cage
(7) Small diameter cage
(8) Lubricant discharge passage

Claims (1)

In the double-row ball bearing that includes the outer ring, the inner ring, a plurality of balls arranged in a double row between the two wheels, and a cage that holds these balls, and the lubricant is moved by the pumping action of the bearing,
A double row ball bearing characterized in that a lubricant discharge passage is provided in the outer ring to discharge the lubricant in the middle part of the double row balls to the outside.

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